1. Field of the Invention
The present invention relates to a wireless communication apparatus.
2. Related Background Art
While PHS (Personal Handy-Phone System) cellular phone may be used as a mobile terminal in a public mobile communication network, it may be accommodated in a home antenna of PHS as an extension terminal.
This home antenna is set up at a location such as a window side of a residence facing a road which is receivable of public radio waves notwithstanding being weak and receives public radio waves and converts them into self-manageable frequencies, so that a plurality of PHS cellular phones arranged in the interior of the residence can receive public incoming calls.
FIG. 1 is a view showing the constitution of the conventional PHS cellular phone system.
In FIG. 1, the PHS cellular phone (1501 to 1505) as the extension terminal performs a communication with a wireless communication apparatus (1511) by using the PHS (1506 to 1510) as communication means (system). This wireless communication apparatus (1511) is the above described home antenna.
The wireless communication apparatus (1511) performs a communication with a base station (1513) by using the PHS (1512) also as communication means.
The base station (1513) is connected with a PHS network (1514), and the PHS network (1514) is connected to a wired network (1515), a PCD network (1516) and a cdmaOne network (1517).
Each mobile communication network (1514, 1515, 1517) is provided with a service control office (SCP: Service Control Point) (1514-1, 1515-1, 1516-1), and the control of each mobile communication terminal is performed here.
FIG. 2 is a flowchart showing the procedure of a call out process performed in the wireless communication apparatus (1511) in the above described conventional PHS cellular phone system.
In FIG. 2, when a call out is made (S1601) from any of the affiliated PHS cellular phone (1501 to 1505), the wireless communication apparatus (1511) determines (S1602) whether the destination terminal of the call out is any of the affiliated PHS cellular phones (1501 to 1505) and, when it is any of the affiliated phones, performs an incoming process for the destination terminal PHS cellular phone (S1603).
On the other hand, when the destination terminal is not any of the affiliated PHS cellular phones (1501 to 1505), a new wireless link is established (S1604) between it and the base station (1513), and call out information such as dial information is notified to the PHS network (1514) (S1605).
FIG. 3 is a flowchart showing the procedure of a disconnection process performed in the wireless communication apparatus (1511) in the above described conventional PHS cellular phone system.
In FIG. 3, within the affiliated PHS cellular phones (1501 to 1505), when a disconnection operation is performed (S1701) in the PHS cellular phone during speech, it is determined (S1702) whether the partner terminal is any of the affiliated PHS cellular phones (1501 to 1505) and, when it is any of the affiliated phones, the disconnection process is performed for the PHS cellular phone of the partner terminal (S1703). When it is not any of the affiliated phones, the disconnection process of the wireless link, which has been established between the wireless communication apparatus and the base station (1513) and used for speech, is performed (S1704).
Note that the PHS cellular phones (1501 to 1505) perform a location registration for the PHS network (1514) when a power source is built up (or when the home antenna is set up) in order to make a public incoming call possible.
FIG. 4 is a view showing a location registration sequence in the above described conventional PHS cellular phone. The location registration will be described with reference to FIG. 4.
When the PHS cellular phone (1501) transmits a location registration request (1801) to the wireless communication apparatus (1511), the wireless communication apparatus (1511), which has received this, converts the radio frequency and the like for a public use and transmits the location registration request (1802) to the base station (1513).
The base station (1513), which has received this, transmits a HLR update request (1803) to a service control office SCP (1514-1) of the PHS network (1514).
A HLR (Home Location Register, 1804) is a data base for controlling subscribers of its own network, which the service control office (SCP) (1514-1) of the PHS network (1514) is provided with.
The HLR (1804) is stored with a subscriber's number of the PHS cellular terminal and a location identification number within the service area showing a location area (LA) of the base station (or one or a plurality of switch boards which accommodate the base station) in whose service area the PHS cellular terminal and the wireless communication apparatus exist.
The service control office SCP (1514-1) which has received the HLR update request (1803) updates the location area (LA) of the base station within the service area of the PHS cellular terminal (1501) in the HLR (1804) to a location area (LA) of the base station (1513) (1804).
In this way, when the location registration normally finishes, a HLR update response (1805) is transmitted from the service control office SCP (1514-1) of the PHS network (1514) and a location registration response (1806) is notified to the wireless communication apparatus (1511) through the base station (1513). The wireless communication apparatus (1511), which has received this, converts the radio frequency and the like for its own use and notifies to the PHS cellular phone (1501) of a location registration response (1807).
Note that the location registration request and the response thereof are simplified for simplicity's sake, which actually include a certifying procedure, a secret designation procedure and the like.
In this way, in the above described conventional PHS cellular phone system, the wireless communication apparatus (1511) wirelessly connects with the PHS cellular phones (1501 to 1505) by the communication means (the communication systems) which are referred to as PHS (1506 to 1510) and further wirelessly connects with the public wireless base station (1513) by the communication means (the communication system) which is referred to as the PHS (1512).
That is, the wireless communication apparatus (1511) is provided only with a single wireless communication means (a wireless communication system) and therefore a cellular phone by way of wireless communication system other than the PHS can not be wirelessly connected with the wireless communication apparatus (1511).
When the PHS wireless cellular phones (1501 to 1505) start communications (call establishment) with the PHS network (1514) through the base station (1513), it is necessary to establish a new link between the wireless communication apparatus (1511) and the base station (1513) (a step S1604 of FIG. 17), which imposes a great load on a limited wireless resource.